Resolution:
1. Check the fan trays and make sure all the fans are powered and working correctly.
2. Check that the foam clamp is fastened tightly around the cables exiting the cabinet otherwise air will be drawn through the gap and straight into the air inlets of the fan modules, thus bypassing the internal equipment.
3. Make sure the equipment is spaced correctly within the cabinet.
4. Make sure the maximum equipment power rating has not been exceeded.
5. Check that nothing is blocking the air intakes or exhausts.
6. Check air filters are not blocked.
7. Make sure the sides of the cabinet are not pushed up against a wall. There should be a gap of 200 mm (8") on each side to allow warm air to exit the fan modules.
8. Make sure the cabinet is not positioned in direct sunlight.